NEW YORK, NY - APRIL 12: (L-R) Marc Staal #18, Carl Hagelin #62 and Brad Richards #19 of the New York Rangers celebrate after teammate Marian Gaborik #10 scored a goal in the second period against the Ottawa Senators in Game One of the Eastern Conference Quarterfinals during the 2012 NHL Stanley Cup Playoffs at Madison Square Garden on April 12, 2012 in New York City. (Photo by Bruce Bennett/Getty Images)

Several Rangers celebrate following Marian Gaborik's goal in the second period against the visiting Senators in Game 1 on April 12, 2012. (credit: Bruce Bennett/Getty Images)

NEW YORK (AP) — The biggest moment of the New York Rangers’ postseason-opening win came when play was stopped, and the top-seeded team in the Eastern Conference tried to catch its breath at the bench.

The Rangers were nursing a one-goal lead in the second period, but the Ottawa Senators were all over them. Coach John Tortorella used his lone timeout, and shifted momentum completely.

Marian Gaborik and Brian Boyle scored minutes apart shortly after, and the Rangers rolled to a 4-2 victory over the Senators on Thursday night.

The Rangers, the No. 1 seed in the East for the first time since they won the Stanley Cup in 1994, shook off their 1-2-1 regular-season mark against the Senators and easily dispatched them in Game 1.

Ryan Callahan scored in the first period, Gaborik and Boyle pushed the lead to 3-0, and Brad Richards added a goal in the third for the Rangers. New York will host the No. 8 Senators again on Saturday night before the best-of-seven series shifts to Ottawa for Games 3 and 4.

“That is the way we have to play to win,” Callahan said. “We felt like we’ve been playing playoff hockey right through the season.

“It’s still a long series left. Taking Game 1 doesn’t mean much.”

Henrik Lundqvist was sharp early, stopping Jason Spezza on a partial breakaway and then turning aside Jim O’Brien, who weaved his way through the New York defense before getting off an in-close drive that was knocked away.

Lundqvist’s only blemishes came in the third period. Daniel Alfredsson wrecked his shutout bid at 10:05, and Erik Condra made it 4-2 with 2:19 left. Lundqvist finished with 30 saves.

Craig Anderson stopped 27 shots, but it wasn’t enough for him to maintain his perfect mark at Madison Square Garden.

The Senators dominated play throughout the second period, but a couple of late lapses turned a tight game into a virtual runaway. They took solace in playing a strong third period.

“It was a pretty even game, but then we got off our game plan for a few minutes and it’s 4-0,” Spezza said. “We have to build off what we did in the third period.

Even with three straight power plays that spanned the first and second periods, the Senators were frustrated by either Lundqvist or players in front of him who dived to block shots from ever getting through.

“We have to get more traffic in front of Lundqvist,” Spezza said. “They are going to block a lot of shots. When he can see it, he’s one of the best.”

Ottawa kept up constant pressure in the New York end during the second period. It just didn’t produce any results. The Senators hemmed in the Rangers several times and forced a handful of icing calls. It got so bad that Tortorella was forced to call timeout to give his guys a breather after back-to-back icings.

“They had the momentum at that point,” Callahan said. “We knew that was going to happen throughout the game, we just had to calm ourselves down and get back to work. I thought we did that after the timeout.”

The Rangers outshot Ottawa 8-2 in the final 10:02 of the second.

After the Rangers killed a questionable tripping call against defenseman Ryan McDonagh, while they nursed a 1-0 lead, Gaborik gave his club a bit of insurance.

The Rangers’ leading scorer got the puck along the right wing boards, after the Senators turned it over in their own end, and drove toward the net. He stopped short in front of Anderson, shifted the puck to either side of his stick while looking for an opening, and then slid a shot into the net to make it 2-0 with 3:36 left in the second.

Gaborik, who scored 41 goals in the regular season, had another in-close chance earlier in the period, but elected to pass instead of shoot. He did it all himself this time in netting the unassisted goal.

“It was a quick 2-on-1,” Gaborik said. “I tried to fake a pass to (Richards) and tried to take it to the net and go five-hole. He opened it up and I am glad it went in.”

The Rangers spent much of the two off days before the series opener working on their anemic power play. It didn’t click late in the second, while Filip Kuba served a hooking call, but New York connected 13 seconds after the defenseman left the box.

Pressure continued to mount in the Ottawa end after the power play expired, and Artem Anisimov lunged to nudge a bouncing rebound in the slot back to Boyle in the right circle. He got just enough of it to set up Boyle, who snapped in a shot with just 53.8 seconds left in the second — 2:42 after Gaborik’s goal — to push the lead to 3-0.

The Senators were outshot 12-11 in the second, but it seemed much more one-sided in Ottawa’s favor until the Rangers’ late strikes.

“The last four or five minutes we give up a couple goals and again early in the third,” Senators coach Paul MacLean said. “Take away those six minutes and we’re pretty happy with how we played the game. We’ll build on the 54 minutes in the game we played reasonably well.”

Callahan was itching to play in the postseason after being forced to miss New York’s first-round loss to Washington last year because of a broken ankle. He made his presence felt throughout the spirited first period.

Callahan netted the first goal of the series when he got to a rebound of Anisimov’s shot from the right point at the bottom edge of the right circle and whipped the puck around Kuba along the ice and between Anderson’s pads with 7:59 left in the first.

The Rangers captain also stepped up at center ice and thwarted a Senators rush when he laid a crushing hit on Ottawa forward Jesse Winchester and sent him flying to the ice with just over two minutes left in the first. Chants of “Call-ie, Call-ie” echoed through the towel-waving crowd at Madison Square Garden that hosted Game 1 of a playoff series for the first time since the first round in 1996 against Montreal.

NOTES: Boyle, who had 11 goals in the regular season, scored five of them in the final nine games. … Lundqvist, who has never advanced past the second round, is 16-20 in 36 postseason games. … Anderson had been 6-0 with a 1.13 goals-against average and two shutouts in his previous Madison Square Garden starts.